Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh tai » thanh tai, han tai, hinh tai
hieu van » hieu va, thien van, lieu va
hang tai » hang va, dung tai
nang cai » nang cao, nang tai, nang cap
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
tai cua » thai cua, tai cuc, tri cua
su sach » so sach, vu sach

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang cai) or (hang tai)) hoi. hieu van ((nang luc) or (am thuc)) va hanh tai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang cai) OR (hang tai)) hoi. hieu van ((nang luc) OR (am thuc)) va hanh tai cua triet.
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang cai) or (hang tai)) hoi. hieu van ((nang luc) or (am thuc)) va hanh tai cua triet*.